Just an idea I had while trying to work out a numeric paging system for our church's nursery. I loaded openlp on on a Raspberry Pi hooked to a monitor that we are going to mount to the wall of the sanctuary. It has a usb wifi dongle that we are able to remotely use with a mobile device. I created a new song where each verse is a different number. changed the theme so the numbers were as big as I could fit on the screen. So then our nursery workers are able to put a number on the monitor from the nursery by using the web interface. It seems to work really well for that. I just thought I would share that idea, because the cheapest systems we have found online for nursery paging were $300 and they went way up from there. This can be done with a raspberry pi and the rest is probably already available to you, and customizable.